Modifying PCI slot fan speed

I recently bought an EVERCOOL SB-F1 to help pull air out of my case (preemptively away from a RAID card/BBU to keep battery temperatures down). While this thing sucks a lot of air, it's a little louder than I would want it to be, so I would like to essentially lower the voltage to decrease the fan speed and ultimately lower the sound it produces. It uses two wires (red and black, I think +5v and ground) connected to a molex connector. I have a Silverstone FP33 fan controller that I have from an old build and thought about using that but of course the connections as it stands are imcompatible, so I have essentially three options:

1: Buy a molex to 3 pin adapter so I can connect it to the controller (assuming that works)
2: Buy just the 3 pin female connector (and find pins) and mod the power connector so I can connect it to the controller (assuming that works)
3: Salvage one of the Rheostats that I am not using from the controller and connect just that directly to the non-ground wire (also assuming that works)

Are any/all of these possible? Which would you personally do and why? (I am open to doing either three, but am unsure which is the potentially better option).

I would buy the adapter because it is the simplest. If it doesn't work, you can put it back to its original configuration quickly and easily. It will still be loud but functional. The other two methods are more destructive and require more work to restore. Also, if the first method doesn't work, you can still try the other two if you want.

Fair enough, that was what I was sort of leaning towards, even if space is at a premium (Well, not really but I'm very picky about cable management). I'm stuffing a Lian Li PC-Q08 with 5 drives, raid controller, and a bunch of other stuff, so I'll just have to find space for one of those adapters and the fan controller.

edit: I found the space for the adapter and fan controller, and now it all works fine.

I recently purchased the EVERCOOL SB-F1 as was hoping to make it a bit quieter as well.

What solution did you end up going with? I was hoping to get plug it into my motherboard's chassis fan plug instead of an independent fan controller. Although I'm not sure if that would work since this fan does have the cable for sensing RPMs.

If it is the same as mine, it has 2 wires that go to a molex connector, right? Unfortunately the only way to slow the fan down is to add electrical resistance, neither of the two wires are for RPM sensing. An independent fan controller does this with the rheostat knobs. The other way to do this is to physically add a resister to the fan electical wire (this requires some electical know how) or actually reduce the amount of power you're sending to the fan (like giving 7v to a 12v fan). For use with my fan controller, I got an adapter on ebay [link]. Note that it is molex to female 3 pin, and while there are daisychain cables that'll let you do this, I wanted a dedicated adapter. If you want to try the less power idea this adapter from the same seller [link] might work too. The rheostat solution lets you choose how fast and how loud/quiet the fan is, while reducing the voltage is essentially all or nothing.